For the Chicken Shawarma, mix oil, vinegar, lemon juice, Spice Blend and salt in small bowl. Place chicken in large resealable plastic bag or glass dish. Add marinade; turn to coat well. Refrigerate 1 hour or longer for extra flavor.
Meanwhile, for the Tahini Yogurt, mix all ingredients in small bowl until well blended. Cover. Refrigerate until ready to serve.
For the Cucumber Radish Relish, mix oil, lemon juice, mint, sea salt, garlic powder and pepper in large bowl. Add cucumber, radishes and green onion; toss to coat well. Cover. Refrigerate until ready to serve.
Preheat oven to 450°F. Remove chicken from marinade. Discard any remaining marinade. Place chicken on foil-lined baking pan.
Roast chicken 15 to 20 minutes or until cooked through. Slice chicken into thin slices. Serve on pita with lettuce, chopped mint, Tahini Yogurt and Cucumber Radish Relish.